The present invention generally relates to a lever type connector and more particularly, to a lever type connector in which first and second connectors brought into telescopic engagement with each other are coupled with each other by using a lever mounted on the first connector, and the lever can be easily operated for its rotation from a temporary stop position where the lever is retained prior to engagement between the first and second connectors.
Conventionally, since a large coupling force is required when first and second connectors of a multipolar connector having 20 terminals or more are brought into telescopic engagement with each other, a lever type connector is provided in which the first and second connectors can be easily coupled with each other by applying a relatively small force by the use of a lever based on the principle of a lever.
As shown in FIG. 1, a known lever type connector includes first and second connectors 1 and 6 brought into telescopic engagement with each other. The first and second connectors 1 and 6 act as a female connector and a male connector, respectively. A lever 2 is rotatably mounted on opposite side faces of the first connector 1 by a pair of rods 3, while a pair of engageable holes 4 are formed on opposite sides of the lever 2, respectively. A pair of pins 5 project from opposite side faces of the second connector 6 so as to be received by the engageable holes 4, respectively when the second connector 6 is fitted into the first connector 1.
Prior to engagement between the first and second connectors 1 and 6, rotation of the lever 2 in the direction of the arrow X is prevented by a stopper 7 projecting from each of the opposite side faces of the first connector 1, and rotation of the lever 2 in the direction of the arrow Y, i.e., in the operational direction of the lever 2, is prevented by a temporary stop member (not shown) based on a detent mechanism through engagement of an inner face of the lever 2 with a corresponding portion of an outer face of the first connector 1 such that the lever 2 is stopped temporarily.
When the second connector 6 is fitted into the first connector 1, the second connector 6 is depressed in the direction of the arrow A into an opening 8 formed in the first connector 1. A slot 9 is formed on each of opposite side walls of the first connector 1, while a recess 10 is formed on each of opposed inner side faces of the lever 2. Thus, the pin 5 is inserted from the slot 9 into the engageable hole 4 through the recess 10. After the pin 5 has been inserted into the engageable hole 4 upon depression of the second connector 6 into the opening 8 of the first connector 1, the lever 2 is rotated in the direction of the arrow Y. As a result, the pin 5 is moved further into the engageable hole 4 through displacement of the lever 2 and thus, the second connector 6 is pulled towards the bottom of the opening 8 such that the first and second connectors 1 and 6 are coupled with each other.
In the known lever type connector of FIG. 1, the engageable hole 4 has an inlet 4a opening in the horizontal direction for inserting the pin 5 into the engageable hole 4, a first guide portion 4b extending horizontally from the inlet 4a and a second guide portion 4c curved upwardly from the first guide portion 4b. Furthermore, an arcuate portion 4d connects the first and second guide portions 4b and 4c.
Since the engageable hole 4 has the above described shape, the pin 5 forced into the engageable hole 4 is firmly fitted into the arcuate portion 4d as shown in FIG. 2. In addition, the lever 2 is stopped temporarily by the stopper as described above. Therefore, the lever 2 cannot be rotated smoothly by cancelling the temporary stop of the lever 2, thereby resulting in poor operational efficiency. Namely, in order to disengage the pin 5 from the arcuate portion 4d of the engageable hole 4, it becomes necessary to either rotate the lever 2 while adjusting a rotational angle of the lever 2 or manually adjust position of the pin 5 relative to the engageable hole 4. Furthermore, in order to cancel the temporary stop of the lever 2, a rotational force exceeding a detent force of the stopper should be applied to the lever 2.
Meanwhile, in multipolar connectors, since frictional resistance between terminals to be connected is large, a large rotational force is required to be applied to the lever 2 in order to couple the first and second connectors 1 and 6. Therefore, a spring is wound around each of the rods 3 of the lever 2 so as to urge the lever 2 in the direction of the arrow Y such that the lever 2 can be rotated with a small force. Even in the case where the lever 2 is not urged in the direction of the arrow Y by the spring, the lever 2 is required to be retained at a temporary stop position prior to fitting of the second connector 6 into the opening 8 of the first connector 1. To this end, the known lever type connector is provided with a temporary stop member for retaining the lever 2 at the temporary stop position prior to coupling of the first and second connectors 1 and 6.
One example of the temporary stop member in a prior art lever type connector is shown in FIG. 3. In FIG. 3, connectors 11 and 14 are coupled with each other by using a lever 13 supported by a rod 19. The prior art temporary stop member includes a stopper 12 and a V-shaped groove 13a formed on the lever 13. A distal end 12a of the stopper 12 is engaged with the groove 13a so as to temporarily stop the lever 13. In FIG. 3, a pin 16 of the connector 14 is engageable with a slot 15 of the connector 11 and a locking pin 18 of the connector 11 is engageable with a slit 17 of the lever 13.
In order to cancel the temporary stop of the lever 13, the lever 13 itself is required to be operated so as to disengage the distal end 12a of the stopper 12 from the groove 13a. Namely, not only when the connectors 11 and 14 are held out of engagement with each other but when the connectors 11 and 14 are held in engagement with each other, the lever 13 is held at the temporary stop position unless an operation for cancelling the temporary stop of the lever 13 is performed.
Therefore, when the connectors 11 and 14 are brought into engagement with each other, the lever 13 cannot be operated for its rotation unless temporary stop of the lever 13 has been cancelled initially. In other words, a large rotational force is required to be applied to the lever 13 at an initial stage of operation of the lever 13, thereby resulting in poor operational efficiency of the lever 13.
Furthermore, as shown in FIG. 4, the known lever type connector of FIG. 1 further includes a lever locking member for locking the lever 2 at the time when the first and second connectors 1 and 6 have been coupled with each other. The lever locking member includes a hollow 28 formed on each of the opposite sides of the lever 2 and a boss 29 engageable with the hollow 28 and projecting from each of the opposite side faces of the second connector 6. As shown in FIG. 5, when the first and second connectors 1 and 6 have been coupled with each-other, the boss 29 is engaged with the hollow 28 so as to lock the lever 2.
As shown in FIG. 6, the hollow 28 of the lever 2 is formed by a mere through-hole and an outer peripheral edge 30 of the hollow 28 has a width L. Therefore, when the boss 29 is brought into engagement with the hollow 28, a large force is required for causing the outer peripheral edge 30 of the hollow 28 to ride over the the boss 29. As a result, an operator finds it difficult to have a sure feeling that the lever has been locked.
The boss 29 has an oblique inlet side face 29a and a vertical outlet side face 29b as shown in FIG. 6. Therefore, the known lever type connector has such a drawback that locking of the lever 2 cannot be cancelled easily.